Control for internal grinders



April 7, 1931.

c. T. RAULE 1,799,763

CONTROL FOR INTERNAL GRINDERS 5 Sheets-Sheet 1 Filed May 21, 1 29 Aprll 7, 1931. c. T. RAULE CONTROL FOR INTERNAL GRINDERS Filed May 21, 1929 3 Sheets-Sheet 2 April 7, 1931. c. T. RAULE CONTROL FOR INTERNAL GRINDERS Filed May 21, 1929 3 Sheets-Sheet '3 IN V EN TOR.

WM ZM* A TTORNEY.

Patented Apr. 7, 1931 UNITED STATES PATENT OFFICE CLIFFORD T. RAULE, OF BROOKLINE, PENNSYLVANIA CONTROL FOR INTERNAL GRINDEBS Application filed May 21,

thereof to its initial position, and to auxiliary safety devices.

A purpose of my invention is to provide an automatic quick-return of a feed screw to its initial position after having completed an operation upon one work piece, preparatory to loading another work piece into the machine thereby avoiding any danger of-engagement between the end of a wheel and a work piece by reason of the feeding operation on a preceding work piece. I preferably use the movement of a gauge when the work piece has been finally brought to required size to effect the quick return in making or breaking an electric circuit, and preferably return the feed member to its initial position by means of a spring. I may also use the gauge as it approaches the unloading position of the machine to electrically stop the turn-table unless and until the piece has been ground to size and unless and until the wheel is out of the way for unloading and loading.

A further purpose'is to combine 'anautomatic loaderwith a quickreturn of the feed members of the individual units in order to bring the work and wheel of successive units into proper alinement for loading.

Further purposes will appear in the specification and in the claims.

My invention is adapted toJnany variant types of multiple spindle grinding machines, using different types of automatic gauges to limit the grinding operations-upon successive 5 work pieces and I have elected to illustrate it as applied to the type of machine disclosed and described in McDonough Patent No. 1,497,574, of June 10, 1924, entitled Internal grinding machines, thus avoiding need for detail description of parts that are not in adapted to O ing a work-holder 1 1929. Serial No. 364,929.

themselves parts of my f'the many types of used I show two only,

present invention.

gauges that might be one of which is generally similar to that disclosed in the McDon ough patent and the other generally in accord with that disclosed 1,225,858, for Automatic in my Patent No.

sizing device.

Figure 1 is a fragmentary top plan view partially diagrammatic and shows my invention embodied upon one of the many types of multiple grinding machines to which it is well adapted to be applied; the view corresponding generally to Figure 2 of the McDonough but modified to embody features of my invention and for greater patent above referred to slmplicity of illustration of the machine shown in ence.

omitting some parts the figure of refer- Figure 2 is a detail elevation partly diagrammatic, illustrating structure embodying my lnvention, with auxili controlling different ope cord with my invention.

Figure 3 is a ary sizing gauge for rations made in acdetail elevation of feed and feed return mechanism embodying some features of my invention illustrating a different form of controlling sizing gauge from that shown the line 33 of the arrows.

Figure4 is a vertical taken upon the line 44 Ike numerals refer to like figures.

Describing in illustration and not in limireferring to the figures the multiple grinding matation, and

Referring to chine shown, Figure 1 is in Figure 2, being a section upon Figure 4 in the direction of section of Figure 3 thereof.

parts in all intended for a conventional illustration of any machine to which the invention is ad The turn-table 10 is apted to be applied. *rotatably 'mounted upon stationary supporting structure 11, lateral brackets 12 of the table carrying wheels 13 which roll round upon a suitable circumferential track 14 of the supporting structure. I

Grinding units are tervals around the table, 5 an unit 16 (only one of each mounted at spaced ineach unit comprisd a grinding wheel shown in Figure 1).

The wheel units with wheels rapidly revolving, traverse at variant heights in vertical i guides 17 of the turn-table which carries the work-holders beneath the respective wheel units, the wheel units being adapted to traverse grind to definite size work pieces 18 in the respective work-holders.

The turn-table is driven by belt 19, pulley 20, shaft 21 and a friction drive disc 22.

The shaft 21 is journaled in suitable bearings 23 at the side of the supporting structure and the periphery of the disc 22 engages the face of a friction wheel 24 that is adapted to rotate the turn-table by mechanism not shown and irrelevant to the present invention. The disc 22 is illustrated as adjustable along its shaft at 25 to vary the rate of rotation of the friction wheel 24.

The work-holder and wheel units may be operatively connected to mechanisms driven by the friction wheel 24-or otherwise as desired, but the drive of the turn-table is desirably independent of that of the wheel and work-holder units and such as to permit stopping rotation of the turn-table without interrupting traverse grinding. Most of the mechanism shown in Figure 1 is described in detail in the McDonough patent referred to.

Work pieces are fed into the successive work-holders by any suitable loader 26 that remains at one position, feeds the work pieces into the holders as they pass and that preferably operates automatically.

The pieces are unloaded after having been ground to size and having made almost complete circuit of the machine by discharge mechanism 27 that preferably operates automatically and is placed some little distance before the loader 26. i

Both the loading and unloading mechanisms may be of any suitable types, as for example such as are already described and claimed by me in one or more copending applications, and are illustrated here diagrammatically, the actual mechanisms being irrelevant to the present invention.

The work-holders are loaded with new pieces as they pass the loader 26 and after they are loaded traverse grinding begins and continues with a gradual feed between the work and wheel units until the pieces are ground to size as determined by individual gauges that may be mounted either upon the individual wheel units above the work pieces or upon the individual work-holders beneath the work pieces.

One type of gauge is illustrated at 28 in Figure 2 and the other type at 28 in Figure 3, and it is to be understood that each grinding unit includes one suitable gauge, of either type.

Figure 3 indicates gauges 28 mounted upon the work-holders and generally similar to the gauges of the McDonough patent, while Figure 2 shows gauges 28 mounted upon the wheel units that are generally similar to the gauges disclosed and claimed by me in my U. S. Patent No. 1,225,858 referred to.

The gauges 28 each including gauge pins 29 and 30 mounted transversely in the upper end of a vertically guided and upwardly pressed gauge carrier 31 that is continuously coaxial with the work piece 18.

The carrier 31 is pressed upwardly by the upper end of a plunger 32 that is slidably mounted in a tubular guide 33 telescoping into a downwardly directed bore of the carrier the guide 33 being rigidly fastened to the turn-table. The plunger is pressed upwardly by a spring 34 inside the tubular guide and is provided with a downwardly extending stem 35 carrying a contact member 36 at its lower end.

The upper gauge pin 29 has a length slightly less than the desired bore of the finished work piece while the lower pin 30 has a length equal to the bore diameter of the finished piece.

Traverse grinding continues with a relative rapid feed between the wheel and work piece until the internal boreof the pieces has become sufficient for the upper gauge pin 29 to follow the traversing wheel upwardly into the work piece,

duce the rate of feed.

Traverse grinding continues at the reduced rate of feed until the internal diameter of the piece is such as to admit the lower pin 30 into the bore of the piece which closes a second circuit, also as disclosed by McDonouglh to stop the feed altogether and to raise t e wheel out of the work piece.

The feed between the wheel and work piece is most desirably automatic and in the Mo- Donough type of machine is effected by screw adjustment of the position of the work-holder with respect to the wheel unit, a ratchet feed of the screw being operated by the traverse motion of the" wheel.

The vertical traverse of the wheel unit vertically reciprocate's a link 37 (Figure 3), to oscillate a rocker member 38.

The hub 39 of the rocker member is loosely mounted upon a shaft 40 that is journaled at 41 and 42 in structure of the turntable and carries a gear 43 which meshes with a gear on the end of a shaft 43' that is adapted to operate the feed screw by intermediate mechanism not shown and irrelevant to the present invention.

Upper and lower arms 44 and 45 of the rocker carry pawls 46 and 47 adapted to engage ratcbet teeth 48 around a wheel 49 keyed to the shaft.

Each time thegrinding wheel 16 traverses up and down there is an oscillation of the rocker member 38 carrying the pawls 46 and of Figure 3 are all alike closing an electric circuit as described in the McDonough patent, to rea collar 69 fastened to a 47 back along the ratchet teeth 48 during the down strokes and forward during the upstrokes to forwardly :feed the ratchet wheel 49. The pawls are provided with adjustable shield members 50 and 51 to keep the pawls during their forward strokes out of operative engagement with the ratchet teeth 48 except during the latter portion of the strokes, the effective strokes of the pawls bein adjusted by changing the positions 0? the shields.

The shields are placed to make the efl'ective strokes of the upper pawl longer than those of the lower paw Electric magnets 52 and. 53 and cooperating armature rocker members 54 and 55, springpressed from the magnets at 56 and 57 respectively are adapted to raise the pawls when the magnets are energized, which is accomplished by determinative movements of the gauges 28 or 28' and circuits.

The sizing gauge 28 (Figure 2) is mounted upon the wheel unit and is generally similar to that disclosed and claimed in my Patent No. 1,225,858, dated -May 15, 1917, entitled Automatic sizingdevice.

In the figure the spindle 58 of the wheel unit carries one or more pairs ofspaced contact members 59, 60 and 61, 62 relatively adcooperating electric 'justable at 63 and 64 respectively and mounted upon the upper ends of rocker members 65 and 66 that extend downwardly with the wheel into the interior of the work piece.

The rocker members are pivotally supported at intermediate points 67 and 68 upon sleeve 70 that surrounds the high speed wheel spindle 58.

The rocker members are spring-presed at 71 so as to tend to spread their lower ends.

During traverse grinding the suitably bulged lower ends 72 of the rockers slide up and down on the interior of the work piece, and gradually spread as the work piece is ground away, causing the opposing contact members on the upper ends of the arms to move toward one another until when the desired diameter has been reached the members 59 and 60 come together energizin the magnet 52 to reduce the rate of feed, a er which traverse grinding continues at the reduced feed until the contact members 61 and 62 come together when the piece has finally come to size, closing a circuit, or circuits, through these contacts to energize the magnet 53 which stops the feed altogether and moves the wheel away from the work piece.

Most of the feed mechanism as thus far described is in the prior art and described in greater detail in. the McDonough patent above referred to.

I provide means for an automatic return of the feed wheel 49 to its original position after a work piece has been ground to size and before a new work piece has been loaded into the work-holder and also means for stopping the turn-table if a grinding unit reaches an designated position, (usually a point just be-- fore unloading position) if the work piece of the unit is not yet ground to size, continuing the grinding stationary until the piece reaches finish size and then raising the.wheel away from the work, starting the turn-table, and effecting spring-return of the feed screw.

Upon the shaft 40 which rigidly carries the feed wheel 49 I mount an auxiliary wheel 73 adapted to rotate upon the feed shaft 40 and spring-connected with the feed wheel 49 by means of a spiral spring 74. One end of this spring is fastened at 75 to the feed wheel and the other end at 76 to the auxiliary anchor wheel 73.

The anchor wheel 73 is externally -V- notched at 77 to receive the bevel end 78 of an inwardly pressing click member 79.

The click member is of square section forwardly beveled to fit the V-notches, longitudinally guided in a radial direction at 80, and internally bored from its rear end to receive the spring 81.

A screw 82 in the outer end of the guide member projects into the bore of the click member to provide means for adjusting the effective strength with which the click member presses inward by suitably changing the compression of the spring 81.

The click member 79 maintains the auxiliary wheel 73 in any set position unlessthe strength tending to move the wheel-is sufficiently great to push back the click member against the action of the spring 81. The notches around the wheel are the same so that the wheel may be held to position at any one of the clicks.

The feed and anchor wheels 49 and 73 are provided with cooperative stop members 83, 84 and 85 that are relatively adjustable and are used to permit variation of the initial spring tension between the wheels and to permit adjustably limiting the angular movement between the wheels.

As illustrated the stop 83 upon the anchor wheel is an abutment across a groove 86 in the face of projecting'run 87 casing the spiral spring between the wheels, and the stops 84 and 85 are screw clamp members mounted along an arcuate slot 88 of the feed wheel and that project into the groove 86 from different positions around the feed wheel.

I obtain any desired initial tension between the feed wheel 49 and the auxiliary wheel 73 by winding the anchor wheel with respect to the feed wheel, then setting the stop member 84 on the feed wheel so that it is adjacent the stop 83 on the anchor wheel.

I also set the second stop member 85 in 'posi- "while the turn-table is tion uponthe other side of the member 83 so as to engage the stop 83at the desired limit of arcuate movement between the two wheels.

In effect the three stops 83, 84 and 85 are two pairs of stops, the member 83 cooperating with the member 84 and also independently cooperating with the member 85. Where it is desired to obtain wider angular movements between the feed and anchor wheels it will be desirable to keep the pairs distinct and at different radial distances from the axis of rotation so as to avoid interference between the stops 84 and 85.

The feed then takes place, as already described, resulting in an angular step by step rotary movement of the feed wheel, by reason of vertical reciprocation of the rod 37 which is suitably connected to the traversing wheel unit.

Normally the anchor wheel does not move during the forward movement of the feed wheel, being held from movement by the click member, and an auxiliary pawl 89 prevents spring-return of the feed wheel 49 when the feed pawls 46 and 47 are both lifted from the feed wheel.

The pawl 89 is adapted to be raised from the teeth of the feed wheel by energizing a magnet 90.

Normally there will be no movement of the auxiliary wheel 73 with respect to the click member after initial setting except at more or less infrequent intervals due to wearing away of the wheel from repeated diamonding and grinding.

After a work piece has been ground to size determinative movement of the sizing gauge 28 or 28' with suitable electric connections controlled by the movement of the gauge successively raise the pawls 46 and 47 from the teeth of the feed wheel which permits the feed wheel to spring back to itsinitial position, thereby avoiding any danger of the end of the wheel striking the inner rim of the new work piece by reason of an inadvertent failure to return the feed wheel by hand or otherwise.

If the forward feed of the feed wheel is greater than the angular distance between the adjustable stop 85 upon the feed wheel and the fixed stop 83 upon the anchor Wheel, these two stops engage and during any continued feed the two wheels move as a unit.

Normally the initial angular distance between these two stops is made merely sufiicient to permit the maximum feed that may be needed with the work pieces to be operated on, which are usually initially of variant and somewhat uncertain sizes, this being the lower limit of safety.

As the wheel wears away the angular movement of the feed wheel gradually increases with successive work pieces until an engagement between the stops 85 and 83 advances the anchor wheel one or more notches at the click member which correspondingly lessens the return movement of the feed wheel to merely that needed for safety.

I preferably do not return the feed wheel 49 to its initial position until the grinding unit, which includes the wheel unit 16 and work-holder 15, reaches a position just before that for unloading, and in the illustration provide connections for effecting the return of the feed wheel 49 always at the same point, preferably a position just before that for unloading and for automatically stopping the turn-table to permit completion of grinding if. a unit comes to this position before its piece has been ground to size, starting the turn-table again as soon as the piece comes to size.

Suitable safety structure and connections (Figures 2 and 3) insure that the grinding operations at the different units are always completed before the the unloading position, by temporarily holding up the rotary movement of the turntable if any unit reaches the designated point a little before the unloading position before completing its grinding operation.

A rocker member 91 is pivoted at 92 adjacent the turn-table 10 and has arms 93 and 94 of which 93 is connected, in any suitable way not shown, to control the operation of the turn-table, preferably without effecting that of the grinding units, radially inward toward the turn-table.

The rocker is spring-pressed at 95 against a stop 96, and when in position against the stop permits rotation of the turn-table, and when deflected away from the stop prevents rotary movement of the turn-table, as by gfi'lecting any suitable shift of gearing or The arm 94 of the rocker carries on its outer end a swinging armature member 97 that has outer and inner positions in which it is respectivel adapted to engage and clear lugs 98 projecting from the turn-table at the respective grinding units.

The armature member 97 is spring-pressed toward its outer position at 99, its outward rlnovement being limited by suitable stop at An electromagnet 101 mounted upon the arm 94 pulls the armature member inwardly when its coil circuit 102 is energized, the armature members swinging back to its outer position when the circuit 102 is broken.

When the armature member is in its outer position it is engaged by any approaching lug 98 upon the turn-table which deflects the rocker and stops rotation of the turn-table, so that the lugs cannot pass the armature member except during periods in which the coil 102 is energized.

The turn-table is thus stopped automatically each time one of the lugs moves into position to engage the armature, that is, each time one of the units comes around to the set position at which grinding must have been completed, unless the magnet is energized,

respective units reach and 94 extends the stoppage of the turn-table not affecting the operation of the diflferent grinding units.

J he electric circuit through the magnet includes spaced slide contacts 103 and 104 which connect at contacts 105 and 106 successively for short periods into the circuits 107 on the turn-table at the individual units each of which includes a member 90 adapted i when energized to effect a return of the feed wheel 49 to its initial-position.

The contacts 105 and 106 carried by the turn-table at each grinding unit are presented across the contacts 103 and 104 when the different units are passing a predetermined position that is somewhat before the position for unloading at 27 and the circuits 107 on the turn-table at the different grinding units also includes open contacts closed by a determinative movement of the gauge 28 or 28 when the work piece reaches finish size.

The magnet 101 can thus not be energized unless and until the piece has come to finish size and also unless and until the turn-table has brought the unit to the selected position so that the turn-table automatically stops any time a piece comes to the selected position without having been yet ground'to size and goes on automatically as soon as the piece comes to size, the contacts 103 and 104 registering with the contacts 105 and 106 during the periods of stoppage.

In operation the work pieces are loaded into the, successive work-holders as they pass a loading point 26, Figure 1. This loading is preferably automatic but may be by hand.

After each unit is loaded, traverse grinding begins at the unit and continues with an automatic screw feed that is efl'ected in the mechanism illustrated by vertical reciprocation of the rod 37 of Figure 2 operating the ratchet feed rocker 38. This reciprocation is conveniently effected by suitable connections to the traversing wheel unit, as described in detail in the McDonough patent.

Traverse grinding continues until the gauge member 28 or 28- makes a determinat1ve movement by reason of the work piece having reached the desired size, which movement is used to close an electric circuit through a member 108 for raising the wheel unit from the work as described in Mc- Donough patent, and the same or other electric circuit through a member 53 for stopping the inward feed between the work piece and wheel.

In Figure 2 this closure is elfected at the contacts 61 and 62 while in the structure of Figure 3 it is efl'ected at the contacts 61 and 36.

Optionally a circuit through the magnet 52 may be closed by an earlier and lesser movement of the gauge to reduce the rate of feed of the feed screw by energizing the magnet 52. This optional circuit is necessary where there are two feeds such as those described by McDonough and illustrated in Figures 2 and 3.

In Figure 2 this earlier closure takes place at the contacts 59 and while in the structure of Figure 3 it takes place at the corresponding contacts 60' and 36 Either before with a resultant stoppage of further of the grinding wheel out of the work piece, due to the determinative movement of the gauge 2801* 28', it reaches the selected polnt a l ttle before the unloading position at which the slide contacts 103 and 104 register with the contacts 105 and 106 on the turn-table and oneof the lugs 98 of the turntable during this registry reaches position to stop rotation of the turn-table unless and until the magnet 101 is energized.

If the magnet 101 has not yet been energized the turn-tablestops leaving the contact members 103 and 104 still engaging the cause the magnet 101 is energized and draws back th of the lug 98 as soon as the contact members 102 and 103 register with the contacts 105 and 10t6, 561d at the saifne time energizes the magne s an 53 to e ect thes rin -r t of the feed wheel. p g e um esirably unloading and loading are automatic, the character of the loading and unloadlng devices bein merel of an suitable kind such, for eximple, is described by me in several copending applications.

The combination between an automatic unloading or an automatic loading device with the automatlc spring-return of the feed screw is particularly advantageous in that it avoids danger of smashing the machine by starting mechanism for traverse grinding before the feed screw has moved into a position to avoid head-on engagement between the ends of the grinding wheel and the top of the Work piece.

In view of my invention and disclosure variations and modifications to meet individual whlm or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown. and I, therefore, claim all such in so far as they fall within the reasonable spirit and. scope of my invention.

Havmg thus described my invention,

what :1:

table and grinding units at spaced intervals therearound, each unit comprising a workholder, a grinding wheel, a shaftadapted to rotate in opposite directions to change the relative alinement of the wheel and holder, a v

ratchet mounted on the feed shaft, an anchor wheel adjacent the ratchet wheel and adapted to rotate, a spiral spring connected at one end to the anchor wheel and at the other end to the ratchet wheel, a spring click yieldably holding the anchor wheel in any set position and permitting angular movement of the anchor wheel with respect to the ratchet wheel and two stops'determining the initial angular position of one wheel with respect to the other, one fastened to each of the wheels.

2. In a multiple grinding machine, a. turntable and grinding units at spaced intervals therearound, each unit comprising a workholder, a grinding wheel, a shaft adapted to rotate in opposite directions to change the relative alinement of the wheel and holder,

a ratchet wheel mounted on the feed shaft, an anchor wheel adjacent the ratchet wheel F and adapted to rotate, a spiral spring connected at one end to the anchor wheel and at the other end to the ratchet wheel, a spring click yieldably holding the anchor wheel in any set position and permitting angular movement of the anchor wheel with respect to the ratchet wheel, two stops determining the initial angular position of one wheel with respect to the other,one fastened to each of the wheels and an adjustment of the initial tension of the spiral spring.

3. In a multi le grinding machine, a turntable and grinding units at spaced intervals therearound, each unit comprising a workholder, a grinding wheel, a shaft adapted to rotate in opposite directions to change the relative alinement of the wheel and holder, a ratchet wheel mounted on the feed shaft, an anchor wheel adjacent the ratchet wheel and adapted to rotate, a spiral s ring connected at one end to the anchor wheel and at the other end to the ratchet wheel, a spring click yieldably holding the anchor wheel in any set position and permitting angular movement of the anchor, wheel with ratchet wheel and two stops determinin the initial angular position of one wheel wit respect to the other, one fastened to each of the wheels and means for adj ustably limiting the forward feed of the ratchet wheel with respect to the anchor wheel.

4. In a multiple grinding machine, a turntable and grinding units at spaced intervals therearound, each unit comprising a workholder, a grinding wheel, a shaft adapted to rotate in opposite directions to change the relative alinement of the wheel and holder, a ratchet wheel mounted on the feed shaft, an

respect to the anchor wheel adjacent the ratchet wheel and adapted to rotate, a spiral spring connected at one end to the anchor wheel and at the other end to the ratchet wheel, a spring click yieldably holding the anchor wheel in any set position and permitting angular movement of the anchor wheel with respect to the ratchet wheel, two stops determining the initial angular position of one wheel with respect to the other, one fastened to each of the wheels, an adjustment for the initial tension of the spiral spring, and an adjustable stop adapted to adjustably limit the forward feed of the ratchet wheel with respect to the anchor wheel.

CLIFFORD T. RAULE. 

